The technique of injection and the results of a series of 124 chemical lumbar sympathectomies, performed on 97 patients, are described. Sixty-eight patients, over 60 years of age, had their sympathectomy because of peripheral arteriosclerotic disease. Fifty-two of these patients benefited in terms of pain relief and only one required amputation. Sixteen patients, under 60 years of age, had their sympathectomy because of peripheral arteriosclerotic disease. Ten of these patients benefited but it is recommended that, where possible, other methods of treatment should be used in this younger age group. Thirteen patients, mostly elderly, had their sympathectomy because of diabetic ischaemic disease. Six only of these patients benefited, but it is felt that chemical sympathectomy can be recommended as a way of helping some of these patients who would otherwise have amputation.